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Take Vitamin B12 To Protect Your Heart
The entire complex of B vitamins is
essential for health, and they’re known as the B complex for
the very good reason that they interact closely together in the
performance of all their vital functions. All the vitamins
of the complex are usually found together in food, and since all
are water soluble, they may also be excreted together from the
body. A deficiency in one of the complex is therefore
usually accompanied by a corresponding deficiency in each of the
others.
That said, there are particular
deficiency characteristics which can be identified for each B
vitamin.
Vitamin B12 (sometimes
known as cobalamin because of the cobalt ion in its composition)
is one of the most important of the complex, and also one of
those in which deficiencies are most likely. These
deficiencies are largely attributable to difficulties in
absorption of the vitamin, which are a particular problem for the
elderly.
Vitamin B12 is required
for the body’s manufacture of the essential amino acid,
methionine, and the associated enzyme, methionine synthase.
An inadequate supply of this enzyme may lead to an excess of
homocysteine, a naturally occurring protein within the body,
which has been associated with an increased risk of
cardiovascular disease. At least 80 separate studies have
noted this association and it seems that the increase in risk is
not negligible. In fact a large study in Europe in 1997
found that people with blood homocysteine levels in the top 20%
of the range faced a more than doubled risk of cardiovascular
disease.
Whilst elevated homocysteine levels
are strongly associated with a deficiency of vitamin B12,
deficiencies of vitamins within the B complex are seldom if ever
found in isolation, and are therefore seldom remedied by single
vitamin supplementation. It is not just vitamin B12,
but vitamins B6 and folic acid, for example, that have
been found to be associated with excess homocysteine, and which
should therefore always be taken together, preferably as part of
a supplement containing the whole B complex.
Given that elevated homocysteine
levels are accepted as a risk factor for cardiovascular disease,
and that supplementation with the vitamins mentioned above is
known to reduce homocysteine levels, you might think it only
commonsense to suppose that an adequate intake of these vitamins,
including B12, would be a protector against
cardiovascular disease. And there are many nutritionists,
of course, who strongly agree with this apparently logical
position. Perhaps surprisingly, then, conventional medicine
remains reluctant to accept it pending the outcome of further
large scale placebo trials.
Science must have its definitive
answer no doubt, and it is a quest which must be respected, but
in this case, given the relatively small amounts of these
vitamins required by the body, and the absence of any reported
toxicity or adverse side effects, it might be wondered whether
from the point of view of the seeker after health, particularly
those no longer in the first flush of youth, it is really worth
running the risk of a deficiency.
And even orthodox opinion recognises
that the risk is real, even though it is unlikely to be caused by
an inadequate dietary supply. The Recommended Dietary
Allowance (RDA) for vitamin B12 is only 2.4 mcg a day,
an amount which should be readily obtainable, except perhaps for
those following a strict vegetarian regime, given that a single 3
oz serving of fish or red meat may provide this quantity. For
those with a taste for it, sea food may provide a great deal
more, and chicken, turkey, eggs, milk and cheese are also useful,
though less lavish, sources.
Deficiencies may well result,
however, from problems with the absorption of the vitamin,
particularly in older people, and it has been estimated that
deficiency may affect 10% -15% of individuals over the age of 60.
This is because good absorption of
vitamin B12 from food is heavily
dependent on the normal stomach acid and digestive enzymes, the
quantity and effectiveness of which decreases substantially as
the body ages, and on the presence in the stomach of a
specialised protein known as Intrinsic Factor. The
correct action of Intrinsic Factor requires the presence of
adequate calcium in the body, another nutrient in which the
elderly, of course, are notoriously likely to be deficient.
Absorption of B12 from
supplements is much less problematic, however, because stomach
acid and digestive enzymes are not required to release the
vitamin from its protein bindings. So this is a rare case
in which even conventional medical “wisdom” recognises
the value of supplementation, at any rate for the over 50s.
But given that sub-optimal levels of
vitamin B12, if not outright deficiencies, are commonly found even
in younger individuals, and that cardiovascular disease is a problem which may
develop insidiously and without symptoms over many years, there would seem to be
strong arguments for supplementation even amongst the wider population.
Steve Smith
September 2007